231111109 has 2 divisors, whose sum is σ = 231111110. Its totient is φ = 231111108.

The previous prime is 231111031. The next prime is 231111149. The reversal of 231111109 is 901111132.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 211557025 + 19554084 = 14545^2 + 4422^2 .

It is a cyclic number.

It is not a de Polignac number, because 231111109 - 2⁷ = 231110981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (231111149) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 115555554 + 115555555.

It is an arithmetic number, because the mean of its divisors is an integer number (115555555).

Almost surely, 2^231111109 is an apocalyptic number.

It is an amenable number.

231111109 is a deficient number, since it is larger than the sum of its proper divisors (1).

231111109 is an equidigital number, since it uses as much as digits as its factorization.

231111109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54, while the sum is 19.

The square root of 231111109 is about 15202.3389318881. The cubic root of 231111109 is about 613.6776036325.

The spelling of 231111109 in words is "two hundred thirty-one million, one hundred eleven thousand, one hundred nine".